A proposal for a 32,000 free-range hen unit in west Wales has been rejected for a second time amid concerns over pollution.

Carmarthenshire Council has refused a planning application for the poultry unit in Llandeilo.

The plans, submitted by Terry Davies, sought to place the unit next to properties and a tributary to the River Tywi at Pentrefelin, Llandeilo.

In its refusal, the council cited an objection by Natural Resources Wales (NRW) regarding airborne pollution from the unit which identified its effect on the Dinefwr Estate more than 1,500m away.

In its rejection letter, the council said: “The Dinefwr Estate Site of Special Scientific Interest is recognised as the second most important site in England and Wales for its parkland lichen assemblage; it is considered the impact from the proposal poses a major risk and will detrimentally impact the special features of the site.

“There are significant concerns that emissions from the proposed free-range housing for both ammonia and nitrogen would reach and detrimentally impact a significant area of the Dinefwr Estate SSSI.

“The findings of the lichen survey demonstrates that ammonia is already adversely influencing the edges of the SSSI. Therefore, it is the opinion of the local planning authority that any proposal which will add any more ammonia to the system will expand these external pollution influences.

“Based on the predictions and conclusions of the Amended Ammonia Report submitted in conjunction with this planning application, there would be an unacceptable exceedance of the critical level, at which the lichen features of the Dinefwr Estate SSSI will be impacted.”

Nature expert Iolo Williams also objected to the plans

Other objections came from the National Trust, South West Wales Wildlife Trust, Botanical Society of Great Britain and Ireland, Fish Legal (the legal arm of the Angling Trust) and several other organisations, as well as from members of the public.

Public Health Wales also advised the council it did not have the information required to make a decision regarding the unit’s impact on public health. It noted the presence of several residences within a 400m radius.

Naturalist and broadcaster Iolo Williams said: “It is madness to allow a chicken farm to be built in such a sensitive part of rural Carmarthenshire, whose rivers are renowned for their salmon and sea trout as well as other riparian species such as otters and little ringed plover.

“The proliferation of chicken farms in rural Wales is of grave concern, both for their threats to wildlife and on moral grounds.”

The plans were a resubmission of a previous similar scheme by Mr Davies, which was withdrawn two years ago.

More than 30,000 chickens could be located at the unit earmarked for land in the Towy Valley, Carmarthenshire

Last autumn Carmarthenshire council turned down another application for a 32,000 free-range hen unit at Godre Garreg farm at Llangadog, near Llandovery.

Nine out of 12 councillors voted to reject the application despite being recommended to accept it.

The vote came after the council received 79 objections and a 1,300-signature petition against the application, with objections focussing on the planned unit’s proximity to houses, noise, smells and concern about the spread of manure.

But David Waters, county executive officer for FUW in Carmarthenshire, spoke out in favour of the application, saying: “It is imperative that potential employment opportunities are explored in all aspects of the rural economy and this proposed development ticks the boxes in many of these areas.”

NFU Cymru, in response to earlier concerns about large-scale poultry units, said: “Welsh farmers need to be able to modernise and diversify their farm holdings and make the most of their land, as well as to ensure the unique Welsh countryside continues to be managed.

“Throughout Wales in recent years, farmers have diversified into free-range egg production in response to growing consumer demand for free-range eggs in the UK. All these developments are subject to stringent planning controls through the local planning authorities, with environmental impact assessments required where livestock units are proposed close to sensitive sites.”